Modelling particle deposition in human lungs: modelling concepts and comparison with experimental data.

Deposition of inhaled particles in the human lung is determined by biological factors, such as lung morphology and respiratory physiology, as well as by physical factors, such as fluid dynamics of the inhaled air and physical deposition mechanisms acting upon inhaled particles. Different conceptual particle deposition models vary primarily with respect to lung morphometry and mathematical modelling technique, rather than by using different deposition equations. Current whole lung deposition models permit the prediction of particle deposition in single airway generations or defined regions of the human lung for any combination of particle size and breathing pattern. Although comparisons with experimental data in human subjects indicate that all presently available deposition models correctly predict total and regional deposition, they cannot be validated by comparison with experimental data at the single airway or airway generation level.